1. Field of the Invention
The present invention relates to an image scanner, and more particularly, to an image scanner with an automatic document feeder and a movable back light source.
2. Description of the Prior Art
Nowadays, image scanners are becoming essential in the office for scanning opaque documents and transparent documents. A typical image scanner comprises a housing with a transparent platform installed on its top for placing a document to be scanned, and a flat panel rotationally connected to the housing. During scanning of a document, the flat panel is lifted away from the transparent platform of the housing, the document is placed on the transparent platform, and then the flat panel is attached to the transparent platform of the housing. This time-consuming process must be repeated several times when many documents are to be scanned. This wastes time. Although some of the image scanners can be equipped with an additional device such as an automatic document feeder for feeding documents or a back light panel for scanning transparent documents, this can become very cumbersome. Moreover, most image scanners can only scan either opaque documents or transparent documents. A dual functional scanner which scans both types of documents requires different locating devices to locate transparent documents of various sizes and is very inconvenient to use. A multi-functional image scanner has a very complex structure and is connected to many components thus making the image scanner very complicated.
It is therefore an objective of the present invention to provide an image scanner with an automatic document feeder and a movable back light source to solve the above mentioned problems.
In a preferred embodiment, the present invention provides an image scanner comprising:
a lower casing having a lower transparent platform on its top for placing a document to be scanned wherein the lower transparent platform can be divided into two separate parts, namely a first part and a second part;
a scanning module moveably installed inside the lower casing for scanning the document;
an upper casing rotationally connected to the lower casing and having an upper transparent window on its bottom wherein when the upper transparent window of the upper casing is physically attached to the lower transparent window of the lower casing, the upper transparent window is positioned above the first part of the lower transparent platform;
a light source moveably installed inside the upper casing and placed above the upper transparent window for providing back light to the document;
an automatic document feeder installed inside the upper casing for carrying documents to be scanned through the second part of the lower transparent platform wherein the automatic document feeder comprises a lid rotationally installed on the upper casing and a sensing device for detecting the position of the lid; and
a control circuit for controlling operations of the image scanner;
wherein when the control circuit senses that the lid is at an xe2x80x9conxe2x80x9d position through the sensing device, the scanning module will be moved to a position under the second part of the lower transparent platform such that the documents carried through the second part of the lower transparent platform by the automatic document feeder can be scanned, and when the control circuit senses that the lid is at an xe2x80x9coffxe2x80x9d position, the light source and the scanning module will be moved under the control of the control circuit to scan a document placed on the first part of the lower transparent platform.
It is an advantage of the present invention that the power output of the motor is transmitted to the automatic document feeder to scan opaque documents and transmitted to the movable light source to scan transparent documents thus making the image scanner multi-functional and easy to use.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment which is illustrated in the various figures and drawings.